Habitat changes in the most important stopover sites for the endangered red-crowned crane in China: a large-scale study.

The red-crowned crane (Grus japonensis) is an endangered bird species that has been listed as one of the Class I National Key Protected Wild Animals of China. This study analyzed the habitat changes in the two most important stopover sites for red-crowned crane (Liao River Estuary and Yellow River Delta National Nature Reserves) from 2000 to 2015. The results showed that the landscape patterns of the important stopover sites of red-crowned crane changed obviously and the potential suitable habitat area (tidal flats and marshland) for the red-crowned crane decreased by 183.3 km2, while the area of human activities (including aquaculture waterbodies, farmland and artificial facilities) increased by 140.3 km2. Landscape fragmentation intensified, which could has negative impacts on the survival of the red-crowned crane during migration. A comparative study confirmed that the reduction in marshlands and increasing landscape fragmentation caused by human activities were the main threats in the Liao River Estuary National Nature Reserve, while human activities and natural factors (such as channel flow, rainfall, and sediment discharge) were the jointly driving factors for the reduction in suitable habitats for red-crowned cranes in the Yellow River Delta National Nature Reserve. We suggest there are some loopholes in the management of the two nature reserves, which need to be strengthened urgently in China.